Display device, touch detection device and electronic apparatus

ABSTRACT

A display device includes: a display layer; plural first electrodes formed to be arranged above the display layer; a shield electrode formed apart from the plural first electrodes so as to surround the whole plural first electrodes along an arrangement surface; an insulating layer; and a semiconductive layer formed opposite to the first electrodes and the shield electrode so as to sandwich the insulating layer, wherein the difference between an average potential of the first electrodes and an average potential of the shield electrode is equal to or less than 0.5V.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/624,024 filed on Jun. 15, 2017, which application is acontinuation of U.S. patent application Ser. No. 14/850,392 filed onSep. 10, 2015, issued as U.S. Pat. No. 9,710,100 on Jul. 18, 2017, whichapplication is a continuation application of U.S. patent applicationSer. No. 13/647,988 filed Oct. 9, 2012, issued as U.S. Pat. No.9,158,421 on Oct. 13, 2015, which application claims priority toJapanese Priority Patent Application JP 2011-227280 filed in the JapanPatent Office on Oct. 14, 2011, the entire content of which is herebyincorporated by reference.

BACKGROUND

The present disclosure relates to a display device having a touchdetection function, a touch detection device and an electronicapparatus.

In recent years, a display device attracts attention, in which a touchdetection device which is a so-called touch panel is mounted on adisplay panel such as a liquid crystal display device or the touch paneland the display panel are integrated and various button images and thelike are displayed on the display panel to thereby enable informationinput instead of normal mechanical buttons. As an input device such as akeyboard, a mouse or a keypad is not necessary in such display devicehaving the touch panel, the display device tends to be widely used notonly in a computer but also in portable information terminals such as acellular phone.

There are some touch-panel systems such as an optical type and aresistive type, and a capacitance type touch panel having a relativelysimple structure as well as capable of realizing low-power consumptionis requested. However, there is a danger that noise (external noise) dueto an inverter fluorescent lamp, AM radio waves, an AC power supply andso on propagates through the touch panel to cause malfunction in thecapacitance type touch panel.

Some types of touch panels for improving resistance to such externalnoise have been proposed. For example, there is proposed, inJP-A-2010-277461 (Patent Document 1), a display device with a touchdetection function which includes plural scanning electrodes (driveelectrodes) and plural detection electrodes (touch detection electrodes)intersecting with the scanning electrodes in a display surface anddetects a touch by using variation of capacitance formed in theseintersections due to external near-field objects. In the display devicewith the touch detection function, the danger of improper detection dueto the external noise is reduced by providing a shield electrode aroundthe touch detection electrodes so as to surround the touch detectionelectrodes.

SUMMARY

As it is generally desirable that the drive electrodes and the touchdetection electrodes are almost invisible in the touch panel, it isexpected that these electrodes are made inconspicuous.

In view of the above, it is desirable to provide a display device, atouch detection device and an electronic apparatus which allowselectrodes to be inconspicuous.

An embodiment of the present disclosure is directed to a display deviceincluding a display layer, plural first electrodes, a shield electrode,an insulating layer, and a semiconductive layer. The plural firstelectrodes are formed to be arranged above the display layer. The shieldelectrode is formed apart from the plural first electrodes so as tosurround the whole plural first electrodes along an arrangement surface.The semiconductive layer is formed opposite to the first electrodes andthe shield electrode so as to sandwich the insulating layer. Thedifference between an average potential of the first electrodes and anaverage potential of the shield electrode is equal to or less than 0.5V.Here, the “semiconductive layer” may have resistivity in a range of, forexample, approximately from 10 [Ω·m] to 10¹³ [Ω·m].

Another embodiment of the present disclosure is directed to a displaydevice including a display layer, plural first electrodes, a shieldelectrode, an insulating layer, and a semiconductive layer. The pluralfirst electrodes are formed to be arranged above the display layer. Theshield electrode is formed apart from the plural first electrodes so asto surround the whole plural first electrodes along an arrangementsurface. The semiconductive layer is formed opposite to the firstelectrodes and the shield electrode so as to sandwich the insulatinglayer. An average potential of the shield electrode is equal to orhigher than an average potential of the first electrodes.

Still another embodiment of the present disclosure is directed to atouch detection device including plural first electrodes, a shieldelectrode, an insulating layer, and a semiconductive layer. The shieldelectrode is formed apart from the plural first electrodes so as tosurround the whole plural first electrodes along an arrangement surface.The semiconductive layer is formed opposite to the first electrodes andthe shield electrode so as to sandwich the insulating layer. Thedifference between an average potential of the first electrodes and anaverage potential of the shield electrode is equal to or less than 0.5V.

Yet another embodiment of the present disclosure is directed to anelectronic apparatus including the display device described above, andcorresponding to a television apparatus, a digital camera, a personalcomputer, a video camera, a portable terminal device such as a cellularphone and the like.

In the display device, the touch detection device and the electronicapparatus according to the embodiments of the present disclosure, whendisturbance noise is applied, it is possible to reduce the danger thatthe disturbance noise is transmitted to the first electrodes as theshield electrode shields the first electrodes. In this case, thedifference between the average potential of the first electrode and theaverage potential of the shield electrode is set to be equal to or lessthan 0.5V.

In the display device according to the another embodiment of the presentdisclosure, when disturbance noise is applied, it is possible to reducethe danger that the disturbance noise is transmitted to the firstelectrodes as the shield electrode shields the first electrodes. In thiscase, the average potential of the shield electrode is set to be equalto or higher than an average potential the first electrodes.

When the display device, the touch detection device and the electronicapparatus according to the embodiments of the present disclosure areused, the electrodes can be made inconspicuous as the difference betweenthe average potential of the first electrodes and the average potentialof the shield electrode is set to be equal to or less than 0.5V.

Also, when the display device according to the another embodiment of thepresent disclosure is used, the electrodes can be made inconspicuous asthe average potential of the shield electrode is set to be equal to orhigher than the average potential of the first electrodes.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A and 1B are views for explaining basic principles of a touchdetection system in a display panel according to an embodiment of thepresent disclosure, showing a state where a finger does not touch ordoes not come close to the display panel;

FIGS. 2A and 2B are views for explaining basic principles of the touchdetection system in the display panel according to the embodiment of thepresent disclosure, showing a state where a finger touches or comesclose to the display panel;

FIGS. 3A and 3B are views for explaining basic principles of the touchdetection system in the display panel according to the embodiment of thepresent disclosure, showing an example of waveforms of a drive signaland a touch detection signal;

FIG. 4 is a block diagram showing a configuration example of the displaypanel according to the embodiment of the present disclosure;

FIG. 5 is a cross-sectional view showing a schematic cross-sectionalstructure of a display device with a touch detection function accordingto a first embodiment;

FIG. 6 is a circuit diagram showing pixel arrangement in the displaydevice with the touch detection function according to the firstembodiment;

FIG. 7 is a perspective diagram showing a structure example of driveelectrodes and touch detection electrodes according to the firstembodiment;

FIG. 8 is an upper surface view showing a structure example of driveelectrodes and touch detection electrodes according to the firstembodiment;

FIGS. 9A and 9B are timing waveform charts showing an operation exampleof touch detection operation in the display panel according to the firstembodiment;

FIG. 10 is a table showing an example of results of a currentapplication test with high temperature in the display panel according tothe first embodiment;

FIG. 11 is a cross-sectional view showing a cross-sectional structure ofa relevant part of the display device with the touch detection functionaccording to the first embodiment with an equivalent circuit;

FIG. 12 is a table showing another example of results of the currentapplication test in the display panel according to the first embodiment;

FIG. 13 is a table showing another example of results of the currentapplication test in a display panel according to a comparative example;

FIG. 14 is a cross-sectional view showing a schematic cross-sectionalstructure of a display device with a touch detection function accordingto a modification example of the first embodiment;

FIG. 15 is a cross-sectional view showing a schematic cross-sectionalstructure of a display device with a touch detection function accordingto a second embodiment;

FIG. 16 is an upper surface view showing a structure example of driveelectrodes and touch detection electrodes according to a modificationexample of the second embodiment;

FIG. 17 is a cross-sectional view showing a structure example of thedrive electrodes and touch detection electrodes according to themodification example of the second embodiment;

FIG. 18 is a perspective view showing an external structure of anapplication example of the display panel to which the embodiment isapplied;

FIG. 19 is an upper surface view showing a structure example of driveelectrodes and touch detection electrodes according to a modificationexample; and

FIG. 20 is a cross-sectional view showing a schematic cross-sectionalstructure of a display device with a touch detection function accordingto another modification example.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be explained indetail with reference to the drawings. The explanation will be made inthe following order.

1. Basic Principles of Capacitance Type Touch Detection

2. First Embodiment (In-cell type)

3. Second Embodiment (On-cell type)

4. Application Examples

<1. Basic Principles of Capacitance Type Touch Detection>

First, basic principles of touch detection in a display panel accordingto an embodiment of the present disclosure will be explained withreference to FIG. 1A to FIG. 3B. A touch detection system is embodied asa capacitance type touch sensor, in which, for example as shown in FIG.1A, a pair of electrodes (a drive electrode E1 and a touch detectionelectrode E2) arranged opposite to each other so as to sandwich adielectric D are used to form a capacitor device. This structure isrepresented as an equivalent circuit shown in FIG. 1B. The driveelectrode E1, the touch detection electrode E2 and the dielectric Dconfigure a capacitor device C1. One terminal of the capacitor device C1is connected to an AC signal source (drive signal source) S and theother terminal P is grounded through a resistor R as well as connectedto a voltage detector (touch detection circuit) DET. When an ACrectangular wave Sg (FIG. 3B) of a given frequency (for example,approximately several kHz to several dozen kHz) is applied from the ACsignal source S to the drive electrode E1 (one terminal of the capacitordevice C1), an output waveform (touch detection signal Vdet) as shown inFIG. 3A appears at the touch detection electrode E2 (the other terminalP of the capacitor device C1). The AC rectangular wave Sg corresponds toan AC drive signal VcomAC which will be described later.

In a state where a finger does not touch (or is not close to) thesensor, a current I0 corresponding to a capacitance value of thecapacitor device C1 flows with charge/discharge to the capacitor deviceC1 as shown in FIG. 1B. A potential waveform of the other terminal P ofthe capacitor device C1 at this time is, for example, as shown by awaveform V0 of FIG. 3A, which is detected by the voltage detector DET.

On the other hand, in a state where a finger touches (or is close to)the sensor, a capacitor device C2 formed by the finger is added to thecapacitor device C1 in series as shown in FIG. 2B. In this state,currents I1 and I2 respectively flow with charge/discharge to thecapacitor devices C1 and C2. A potential waveform of the other terminalP of the capacitor device C1 is, for example, as shown by a waveform V1in FIG. 3A, which is detected by the detector DET. At this time, apotential of the point P is a divided potential fixed by values of thecurrents I1 and I2 flowing in the capacitor devices C1 and C2.Accordingly, the waveform V1 will be a lower value than the waveform V0in the non-contact state. The voltage detector DET compares the detectedvoltage to a given threshold voltage Vth and determines the state as thenon-contact state when the detected voltage is equal to or higher thanthe threshold voltage, whereas determines the state as the contact statewhen the detected voltage is lower than the threshold voltage. The touchdetection can be performed in the above manner.

2. First Embodiment Configuration Example Entire Configuration Example

FIG. 4 shows a configuration example of a display panel according to anembodiment. A display panel 1 is a so-called in-cell type display panelin which a liquid crystal display panel and a capacitance type touchpanel are integrally formed.

The display device 1 includes a control unit 11, a gate driver 12, asource driver 13, a drive electrode driver 16, a display device with atouch detection function 10 and a touch detection unit 40.

The control unit 11 is a circuit supplying control signals to the gatedriver 12, the source driver 13, the drive electrode driver 16 and thetouch detection unit 40 respectively based on a video signal Vdisp andcontrolling these units to operate in synchronization with one another.

The gate driver 12 has a function of sequentially selecting onehorizontal line to be a target of display driving in the display devicewith the touch detection function 10 based on the control signalsupplied from the control unit 11. Specifically, the gate driver 12applies a scanning signal Vscan to gates of TFT devices Tr of pixels Pixthrough scanning signal lines GCL to thereby sequentially select oneline (one horizontal line) as a target of display driving in the pixelsPix formed in matrix in a liquid crystal display device 20 of thedisplay device with the touch detection function 10 as described later.

The source driver 13 is a circuit supplying a pixel signal Vpix torespective pixels Pix (described later) of the display device with thetouch detection function 10 based on the control signal supplied fromthe control unit 11. Specifically, the source driver 13 supplies thepixel signal Vpix to respective pixels Pix included in one horizontalline sequentially selected by the gate driver 12 respectively throughpixel signal lines SGL. Then, display of one horizontal line isperformed in accordance with the supplied pixel signal Vpix in thesepixels Pix.

The drive electrode driver 16 is a circuit supplying a drive signal Vcomto drive electrodes COML (described later) of the display device withthe touch detection function 10 based on the control signal suppliedfrom the control unit 11. Specifically, the drive electrode driver 16sequentially applies the drive signal Vcom having an AC rectangularwaveform to the drive electrodes COML in a time sharing manner. Then, atouch detection device 30 of the display device with the touch detectionfunction 10 outputs a touch detection signal Vdet from plural touchdetection electrodes TDL (described later) based on the drive signalVcom to be supplied to the touch detection unit 40.

The display device with the touch detection function 10 is a displaydevice having the touch detection function. The display device with thetouch detection function 10 has the liquid crystal display device 20 andthe touch detection device 30. The liquid crystal display device 20 is adevice performing display by sequentially scanning horizontal lines oneby one in accordance with the scanning signal Vscan supplied from thegate driver 12. The touch detection device 30 operates based on theabove basic principles of the capacitance type touch detection andoutputs the touch detection signal Vdet.

FIG. 5 shows an example of a cross-sectional structure of a relevantpart of the display device with the touch detection function 10. Thedisplay device with the touch detection function 10 includes a pixelsubstrate 2, a counter substrate 3 arranged opposite to the pixelsubstrate 2 and a liquid crystal layer 6 inserted between the pixelsubstrate 2 and the counter substrate 3.

The pixel substrate 2 includes a transparent substrate 21, the driveelectrodes COML and pixel electrodes 23. The transparent substrate 21functions as a circuit substrate on which various types of electrodesand wiring, thin film transistors (TFT) and the like are formed, whichis made of, for example, glass. The drive electrodes COML are formed onthe transparent substrate 21. The drive electrodes COML are electrodesfor supplying a common voltage to plural pixels Pix (described later).The drive electrodes COML function as common drive electrodes for liquidcrystal display operation as well as function as drive electrodes fortouch detection operation. An insulating layer 22 is formed over thedrive electrode COML and the pixel electrodes 23 are formed thereon. Thepixel electrodes 23 are electrodes for supplying the pixel signal Vpix,having transparency. The drive electrodes COML and the pixel electrodes23 are made of, for example, ITO (Indium Tin Oxide). An alignment film24 is formed over the pixel electrodes 23. A polarizing plate 25 isarranged on a surface of the transparent substrate 21, which is oppositeto the surface on which the drive electrodes COML and so on are formed.

The counter substrate 3 includes a transparent substrate 31, colorfilters 32, touch detection electrodes TDL, a shield electrode SH, anadhesive layer 34 and a polarizing plate 35. The transparent substrate31 is made of, for example, glass in the same manner as the transparentsubstrate 21. On the transparent substrate 31, the color filters 32 areformed. The color filters 32 are formed by regularly arranging, forexample, three color filter layers of red (R), green (G) and blue (B),in which three colors of R, G and B are associated with respectivedisplay pixels as a group. An alignment film 33 is formed on the colorfilters 32. The touch detection electrodes TDL and the shield electrodeSH are formed on a surface of the transparent substrate 31, which isopposite to the surface on which the color filters 32 and so on areformed. The shield electrode SH is formed for protecting the touchdetection electrodes TDL from external noise. The touch detectionelectrodes TDL and the shield electrode SH are electrodes made of, forexample, ITO, and having transparency. The polarizing plate 35 isarranged above the touch detection electrodes TDL and the shieldelectrode SH so as to sandwich the adhesive layer 34. The resistivity ofthe polarizing plate 35 is, for example, approximately 10¹³ [Ω·m].

The liquid crystal layer 6 functions as a display function layer,modulating light transmitting through the layer in accordance with astate of an electric field. The electric field is formed by a potentialdifference between a voltage of the drive electrodes COML and a voltageof the pixel electrodes 23. Lateral-electric field mode liquid crystalsuch as FFS (fringe field switching) or IPS (in-plane switching) is usedfor the liquid crystal layer 6.

FIG. 6 shows a configuration example of a pixel structure in the liquidcrystal display device 20. The liquid crystal display device 20 hasplural pixels Pix arranged in matrix. Each pixel Pix includes threesub-pixels SPix. Respective sub-pixels SPix respectively correspond tothree colors (RGB) of the color filters shown in FIG. 5. Each sub-pixelSPix includes a TFT device Tr and a liquid crystal device LC. The TFTdevice Tr is formed by a thin film transistor, which is an n-channel MOS(Metal Oxide Semiconductor) type TFT in this example. A source of theTFT device Tr is connected to a pixel signal line SGL, a gate isconnected to a scanning signal line GCL and a drain is connected to oneterminal of a liquid crystal device LC. The liquid crystal device LC isconnected to the drain of the TFT device Tr at one terminal and isconnected to the drive electrode COML at the other terminal.

The sub-pixel SPix is connected to other sub-pixels SPix belonging tothe same row of the liquid crystal display device 20 to one another bythe scanning signal line GCL. The scanning signal line GCL is connectedto the gate driver 12 and the scanning signal Vcan is supplied from thegate driver 12. The sub-pixel SPix is also connected to other sub-pixelsSPix belonging to the same column of the liquid crystal display device20 to one another by the pixel signal line SGL. The pixel signal lineSGL is connected to the source driver 13 and the pixel signal Vpix issupplied from the source driver 13.

Moreover, the sub-pixel SPix is connected to other sub-pixels SPixbelonging to the same row of the liquid crystal display device 20 to oneanother by the drive electrode COML. The driver electrode COML isconnected to the drive electrode driver 16 and the drive signal Vcom issupplied from the drive electrode driver 16.

According to the above configuration, one horizontal line issequentially selected by driving the scanning signal lines GCL by thegate driver 12 so as to perform line-sequential scanning in thetime-sharing manner, and display is performed in units of horizontallines by supplying the pixel signal Vpix to pixels Pix belonging to onehorizontal line by the source driver 13 in the liquid crystal displaydevice 20.

FIG. 7 perspectively shows a configuration example of the touchdetection device 30. FIG. 8 shows an example of an upper surfacestructure of the touch detection device 30. The touch detection device30 includes the drive electrodes COML provided in the pixel substrate 2and the touch detection electrodes TDL provided in the counter substrate3.

The drive electrodes COML have a strip-shaped electrode patternextending in a right and left direction of FIG. 8. A connection pad 29for connecting to the drive electrode driver 16 is formed at one end ofeach drive electrode COML. When performing touch detection operation,the drive signal Vcom is sequentially supplied to respective electrodesof the pattern and sequential scanning drive is performed in the timesharing manner. The touch detection electrodes TDL have a strip-shapedelectrode pattern extending in a direction (up and down direction inFIG. 8) orthogonal to the extending direction of the electrode patternof the drive electrodes COML. A connection pad 39 for connecting to thetouch detection unit 40 is formed at one end of each touch detectionelectrode TDL. In the example, respective connection pads 39 are formedin a vicinity of common one edge on the surface on which the touchdetection electrodes TDL are formed. A DC current Vsens is applied tothe touch detection electrodes TDL through high resistance as describedlater. In the electrode patterns of the drive electrodes COML and thetouch detection electrode TDL intersecting each other, capacitance isformed at intersections.

According to the above structure, the drive signal Vcom applied to thedrive electrodes COML by the drive electrode driver 16 is transmitted tothe touch detection electrodes TDL and outputted from the touchdetection electrodes TDL as the touch detection signal Vdet. That is,the drive electrodes COML correspond to the drive electrode E1 and thetouch detection electrodes TDL correspond to the touch detectionelectrode E2 in the basic principles of touch detection shown in FIG. 1Ato FIG. 3B. The touch detection device 30 detects a touch in accordancewith the basic principles. As shown in FIG. 8, the electrode patternsintersecting each other configure the capacitance-type touch sensor in amatrix form. Therefore, scanning is performed over the entire touchdetection surface of the touch detection device 30, thereby detecting aposition where an external near-field object touches or comes close tothe sensor.

The shield electrode SH is formed around the touch detection electrodesTDL so as to surround the touch detection electrodes TDL as shown inFIG. 7 and FIG. 8. The shield electrode SH is formed so that anarrangement area is smaller than the total arrangement area of the touchdetection electrodes TDL. In the example, the shield electrode SH isformed so as to surround the touch detection electrodes TDL from threedirections other than a direction of the edge where the connection pads39 of the touch detection electrodes TDL are formed. Accordingly, theshield electrode SH is arranged, for example, in a gap between endportions of a mobile device where a user's hand touches and the touchdetection electrodes TDL when the user holds the mobile device on whichthe display panel 1 is mounted in a hand.

A DC voltage Vsh is applied to the shield electrode SH. In the example,the DC voltage Vsh is approximately the same as the DC voltage Vsensapplied to the touch detection electrodes TDL through high resistance.The DC voltage Vsh may be supplied to the shield electrode SH constantlyas well as for given periods before and after the touch detection signalVdet outputted from the touch detection electrodes TDL makes transition.

According to the above configuration, even when, for example, externalnoise is caught by the user holding the mobile device on which thedisplay panel 1 is mounted as an antenna, and the noise is transmittedto the display panel 1 through the user's hand, the noise is shielded bythe shield electrode SH, therefore, the danger that the noise istransmitted to the touch detection electrodes TDL can be reduced as wellas the danger of improper detection due to the external noise can bereduced.

It is preferable that the shield electrode SH is arranged outside thedisplay surface (outside an effective display area) of the displaydevice with the touch detection function 10.

As shown in FIG. 8, it is preferable that gaps between the shieldelectrode SH and the touch detection electrodes TDL (a gap D1 in the upand down direction and a gap D2 in the right and left direction) areapproximately the same as or larger than a gap D3 of two touch detectionelectrodes TDL adjacent to each other. In this case, parasiticcapacitance between the shield electrode SH and the touch detectionelectrodes TDL can be reduced and effects due to the parasiticcapacitance can be reduced at the time of detecting contact/non-contact.Here, the “gap” indicates a gap at a portion where two electrodes to betargets are positioned closest to each other.

The shield electrode SH is preferably made of the same material as thetouch detection electrodes TDL. In this case, it is possible tosimultaneously form the shield electrode SH and the touch detectionelectrodes TDL in manufacturing processes, which can reduce the numberof processes and the number of masks as compared with the case where theshield electrode SH and the touch detection electrodes TDL are made ofmaterials different from each other.

The touch detection unit 40 is a circuit detecting whether the touchdetection device 30 has been touched or not based on the control signalsupplied from the control unit 11 and the touch detection signal Vdetsupplied from the touch detection device 30 of the display device withthe touch detection function 10 and calculating coordinates in the touchdetection area when the device is touched. The touch detection unit 40includes an LPF (Low Pass Filter) unit 42, an A/D converter 43, a signalprocessing unit 44, a coordinate extraction unit 45 and a detectiontiming control unit 46.

The LPF unit 42 is a low-pass filter which removes high frequencycomponents (noise components) included in the touch detection signalVdet supplied from the touch detection device 30 and takes out touchcomponents to thereby output these components respectively. ResistancesR with a high resistance value are connected to respective inputterminals of the LPF unit 42, and the DC voltage Vsens is appliedthrough the resistance R. It is also preferable that, for example,switches are provided instead of the resistances R and that the DCvoltage Vsens is applied by turning on the switches at given time.

The A/D converter 43 is a circuit for sampling an analog signaloutputted from the LPF unit 42 and converting the signal into a digitalsignal respectively at timings in synchronization with the AC drivesignal VcomAC. The signal processing unit 44 is a logic circuit fordetecting whether the touch detection device 30 has been touched or notbased on the output signal of the A/D converter 43. The coordinateextraction unit 45 is a logic circuit for calculating coordinates in thetouch panel when the touch has been detected in the signal processingunit 44. The detection timing control unit 46 has a function ofcontrolling these circuits to operate in synchronization with oneanother.

Here, the touch detection electrodes TDL correspond to “firstelectrodes” according to an embodiment of the present disclosure. Theadhesive layer 34 corresponds to an “insulating layer” according to theembodiment of the present disclosure. The polarizing plate 35corresponds to a “semiconductive layer” according to the embodiment ofthe present disclosure.

Operation and Effect

Subsequently, operation and effect of the display panel 1 according tothe embodiment will be explained.

(Whole Operation Summary)

First, the whole operation summary of the display panel 1 will beexplained with reference to FIG. 4. The control unit 11 respectivelysupplies control signals to the gate driver 12, the source driver 13,the drive electrode driver 16 and the touch detection unit 40 andcontrols these units to operate in synchronization with one another.

The gate driver 12 supplies the scanning signal Vscan to the liquidcrystal display device 20 and sequentially selects one horizontal lineto be a target of display driving. The source driver 13 supplies thepixel signal Vpix to respective pixels Pix included in one horizontalline selected by the gate driver 12. The drive electrode driver 16sequentially applies the drive signal Vcom to the drive electrodes COML.The display device with the touch detection function 10 performs displayoperation as well as performs touch detection operation based on thedrive signal VCOM to output the touch detection signal Vdet from thetouch detection electrodes TDL.

The touch detection unit 40 detects a touch on the touch detectionsurface based on the touch detection signal Vdet. Specifically, the LPFunit 42 removes high frequency components included in the touchdetection signal Vdet and takes out touch components to thereby outputthese components. The A/C converter 43 converts analog signals outputtedfrom the LPF unit 42 into digital signals. The signal processing unit 44detects whether the touch detection surface has been touched or notbased on output signals of the A/D converter 43. The coordinateextraction unit 45 calculates coordinates in the touch panel when thetouch has been detected in the signal processing unit 44. The detectiontiming control unit 46 controls the LPF unit 42, the A/C converter 43,the signal processing unit 44 and the coordinate extraction unit 45 tooperate in synchronization with one another.

FIGS. 9A and 9B show an operation example of touch detection operation,in which FIG. 9A shows a waveform of the drive signal Vcom and FIG. 9Bshows a waveform of the touch detection signal Vdet. The drive electrodedriver 16 sequentially applies the drive signal Vcom having the ACrectangular waveform shown in FIG. 9A to the drive electrodes COML. Thedrive signal Vcom is transmitted to the touch detection electrodes TDLthrough capacitance and the touch detection signal Vdet changes (FIG.9B). Specifically, the touch detection signal Vdet makes transition withthe transition of the drive signal Vcom to converge to the voltage Vsensafter a given period of time. That is, an average value of voltage(average voltage Vave) in the touch detection signal Vdet isapproximately the same as the voltage Vsens. The A/D converter 43samples the output signal of the LPF unit 42 to which the touchdetection signal Vdet is inputted and performs A/D conversion atsampling timings ts1 and ts2 in synchronization with the drive signalVcom (FIG. 9B). The sampling timing ts1 is provided just before thetransition timing of the drive signal Vcom and the sampling timing ts2is provided just after the transition timing of the drive signal Vcom.In the signal processing unit 44 in the touch detection unit 40, thetouch detection is performed based on the difference between an A/Dconversion result at the sampling timing ts1 and an A/D conversionresult at the sampling timing ts2.

As shown in FIGS. 9A and 9B, the voltage Vsens (average voltage Vave) isset to be, for example, approximately the half of a power supply voltagein the display panel 1 (for example, 1.4V) as the touch detection signalVdet is an AC signal. On the other hand, when shielding external noiseand so on in the electronic apparatus, for example, a voltage of 0V iscommonly used. However, there may cause a problem when the display panel1 is operated in the above voltage setting. The example will beexplained below.

(Discoloration of Touch Detection Electrodes TDL)

A current application test with high temperature was performed to thedisplay panel 1 for evaluating reliability. At this time, discolorationof the touch detection electrodes TDL was confirmed in certainconditions. The details thereof will be explained below.

FIG. 10 shows an example of results of the current application test withhigh temperature. FIG. 10 represents a visual state of the touchdetection electrodes TDL in a temperature condition of 70° C. aftercurrent was applied to the display panel 1 for a given period of time.In the example, the arrangement area of the shield electrode SH isapproximately 1/10 of the total arrangement area of the touch detectionelectrodes TDL.

As shown in FIG. 10, in the case where the current application test withhigh temperature was performed by setting the average voltage Vave ofthe touch detection signal Vdet to 1.4V as well as the voltage Vsh ofthe shield electrode SH to 1.4V, the touch detection electrodes TDL arenot visually recognized and a preferable state is maintained. On theother hand, in the case where the current application test with hightemperature was performed by setting the average voltage Vave of thetouch detection signal Vdet to 1.4V as well as the voltage Vsh of theshield electrode SH to 0V, the touch detection electrodes TDL werediscolored to white.

That is, the touch detection electrodes TDL were not visually recognizedwhen the voltage Vsh was equal to the average voltage Vave, whereas thetouch detection electrodes TDL were visually recognized when a potentialdifference between the voltage Vsh and the average voltage Vave werelarge.

It can be considered that this is because the potential of thepolarizing plate 35 was set based on the voltage Vsh of the shieldelectrode SH and the average value Vave of the touch detection signalVdet and thus ions included in, for example, the adhesive layer 34 weremoved as well as the composition of an electrode material of the touchdetection electrodes TDL was changed. The details thereof will beexplained.

FIG. 11 represents a cross-section of part of the display device withthe touch detection function 10 with an equivalent circuit. As theshield electrode SH and the polarizing plate 35 are arranged so as tosandwich the adhesive layer 34, a resistance Rsh exists between theshield electrode SH and the polarizing plate 35. Additionally, the touchdetection electrodes TDL and the polarizing plate 35 are also arrangedso as to sandwich the adhesive layer 34, resistances Rtd1 exist betweenthe touch detection electrodes SH and the polarizing plate 35. In thepolarizing plate 35, resistances exist as distribution constants.Therefore, the potential of the polarizing plate 35 can be set by adivided voltage of the resistance Rsh, resistances of the polarizingplate 35 and the resistances Rtd1 based on the voltage Vsh of the shieldelectrode SH and the voltage of the touch detection electrodes TDL (theaverage voltage Vave of the touch detection signal Vdet).

For example, when the average voltage Vave of the touch detectionsignals Vdet is 1.4V and the voltage Vsh of the shield electrode SH is0V, the polarizing plate 35 is set to a given potential between 0V and1.4V as the voltage is divided as described above. Accordingly, anelectric field is formed between the polarizing plate 35 and the touchdetection electrodes TDL, and ions in the adhesive layer 34 are moved bythe electric field. Then, chemical reaction occurs or the composition ischanged in the electrode material of the touch detection electrodes TDLdue to the movement of ions, which makes the touch detection electrodesTDL visually recognized. The reason that the touch detection electrodesTDL look white may depend on properties of ions.

According to the above consideration, it can be considered that thetouch detection electrodes TDL become visually recognized in proportionas the voltage Vsh of the shield electrode deviates from the averagevoltage Vave of the touch detection signal Vdet. Next, degrees ofpotential difference in which the touch detection electrodes TDL becomevisually recognized will be explained.

FIG. 12 shows an example of results of the current application test withhigh temperature in the case where the voltage Vsh of the shieldelectrode SH was set to various voltages. In columns of determinationresults, “o” represents that the touch detection electrodes TDL were notvisually recognized, “x” represents that the touch detection electrodesTDL were visually recognized and “4” represents that the touch detectionelectrodes TDL were visually recognized by some people. In the example,the average voltage Vave of the touch detection signal Vdet was fixed to1.4V.

When the voltage Vsh of the shield electrode SH was lower than theaverage voltage Vave (1.4V) of the touch detection signal Vdet, thetouch detection electrodes TDL were discolored to white. The touchdetection electrodes TDL were visually recognized by some people at avoltage Vsh=0.9V (Vsh−Vave=−0.5V) and were visually recognized by manypeople at a voltage Vsh=0.8V (Vsh−Vave=−0.6V).

On the other hand, when the voltage Vsh of the shield electrode SH washigher than the average voltage Vave (1.4V) of the touch detectionsignal Vdet, the touch detection electrodes TDL were discolored toblack, and the touch detection electrodes TDL were visually recognize bymany people at a voltage Vsh=2.0V (Vsh−Vave=0.6V).

Though the average voltage Vave of the touch detection signal Vdet wasset to 1.4V in the example, the same test results were obtained when theaverage voltage was set to other voltages.

As described above, the touch detection electrodes TDL are seendifferently according to the relation in level between the voltage Vshof the shield electrode SH and the average voltage Vave of the touchdetection signal Vdet. That is, when the voltage Vsh is lower than theaverage voltage Vave, the touch detection electrodes TDL look white,whereas when the voltage Vsh of the shield electrode SH is higher thanthe average voltage Vave, the touch detection electrodes TDL look black.It can be considered that the difference in color is caused by, forexample, the difference in absorption reaction or desorption reaction(oxidation-reduction reaction) with respect to the touch detectionelectrodes TDL, which depends on the relation in level between thevoltage Vsh and the average voltage Vave.

The touch detection electrodes TDL are not recognized easily when thevoltage Vsh of the shield electrode SH is higher than the averagevoltage Vave. That is, the touch detection electrodes TDL are notvisually recognized when the potential difference between the voltageVsh and the average voltage Vave is equal to or less than 0.4V in thecase where the voltage Vsh is lower than the average voltage Vave,whereas the touch detection electrodes TDL are not visually recognizedwhen the potential difference between the voltage Vsh and the averagevoltage Vave is equal to or less than 0.5V in the case where the voltageVsh is higher than the average voltage Vave. This may be because thetouch detection electrodes TDL are discolored to black when the voltageVsh of the shield electrode SH is higher than the average voltage Vaveand are not recognized easily as compared with the case where theelectrodes are discolored to white.

Consequently, the touch detection electrodes TDL can be madeinconspicuous by setting the voltage Vsh of the shield electrode SH in arange from a voltage (Vave-0.4V) to a voltage (Vave+0.5V) (1V to 1.9Vwhen the average voltage Vave is 1.4V).

COMPARATIVE EXAMPLE

Next, a display panel 1R according to a comparative example will beexplained as well as effects of the present embodiment will be explainedin comparison with the comparative example. In a display panel 1R, theshield electrode SH and the touch detection electrodes TDL are formed sothat the arrangement area of the shield electrode is equivalent to thetotal arrangement area of the touch detection electrodes TDL.

FIG. 13 shows an example of results of the current application test withhigh temperature in the display panel 1R. In the example, when thevoltage Vsh of the shield electrode SH was lower than the averagevoltage Vave of the touch detection signal Vdet (1.4V), the touchdetection electrodes TDL were discolored to white. The touch detectionelectrodes TDL were visually recognized by some people at a voltageVsh=0.9V (Vsh−Vave=−0.5V) and were visually recognized by many people ata voltage Vsh=0.8V (Vsh−Vave=−0.6V). On the other hand, when the voltageVsh of the shield electrode SH was higher than the average voltage Vaveof the touch detection signal Vdet (1.4V), the touch detectionelectrodes TDL were discolored to black. The touch detection electrodesTDL were visually recognized by some people at a voltage Vsh=1.9V(Vsh−Vave=0.5V) and were visually recognized by many people at a voltageVsh=2.0V (Vsh−Vave=0.6V).

That is, the touch detection electrodes TDL are not visually recognizedin the case where the voltage Vsh of the shield electrode SH is within arange from a voltage (Vave-0.4V) to a voltage (Vave+0.4V) (1V to 1.8Vwhen the average voltage Vave is 1.4V) in the example. In short, therange of the voltage Vsh in which the touch detection electrodes TDL arenot visually recognized in the display panel 1R according to thecomparative example is narrower than the case of the display panel 1according to the present embodiment (FIG. 12). Specifically, in the casewhere the voltage Vsh of the shield electrode SH is a voltage(Vave+0.5V) (1.9V when the average voltage Vave is 1.4V), the touchdetection electrodes TDL are not visually recognized in the displaypanel 1 according to the present embodiment (FIG. 12), however, thetouch detection electrodes TDL are visually recognized in the displaypanel 1R according to the comparative example (FIG. 13).

In the display panel 1R, the arrangement area of the shield electrode SHis equivalent to the total arrangement area of the touch detectionelectrodes TDL. Accordingly, the resistance Rsh shown in FIG. 11 isreduced as well as the resistances Rtd1 are increased in the displaypanel 1R according to the comparative example as compared with the caseof the display panel 1 according to the present embodiment. Therefore,as the potential difference between the voltage of the polarizing plate35 and the voltage of the touch detection electrodes TDL (the averagevoltage Vave of the touch detection signal Vdet) is larger than the caseof the display panel 1 according to the present embodiment, the electricfield between the polarizing plate 35 and the touch detection electrodesTDL becomes higher, ions in the adhesive layer 34 are easily moved andthe touch detection electrodes TDL are liable to be discolored.

On the other hand, the arrangement area of the shield electrode SH issmaller than the total arrangement area of the touch detectionelectrodes TDL. Accordingly, as the potential difference between thevoltage of the polarizing plate 35 and the average voltage Vave of thetouch detection signal Vdet can be smaller than the case of the displaypanel 1R according to the comparative example, movement of ions in theadhesive layer 34 can be suppressed and discoloration of the touchdetection electrodes TDL can be also suppressed.

Effects

As described above, as the potential difference between the voltage ofthe shield electrode and the average voltage of the touch detectionsignal is set to be equal to or less than 0.5V in the presentembodiment, the discoloration of the touch detection electrodes can besuppressed and the touch detection electrodes can be made inconspicuous.

As the voltage of the shield electrode is set to be equal to or higherthan the average voltage of the touch detection signal in the presentembodiment, the range of the voltage of the shield electrode in whichthe touch detection electrodes are inconspicuous can be wider than thecase where the voltage of the shield electrode is set to be lower thanthe average voltage of the touch detection signal. Particularly, forexample, when the voltage of the shield electrode is equal to theaverage voltage of the touch detection signal, the voltage Vsh and thevoltage Vsens (average voltage Vave) can be generated by a commonreference power supply, therefore, a circuit configuration can besimplified.

Additionally, as the arrangement area of the shield electrode is smallerthan the total arrangement area of the touch detection electrodes,movement of ions in the adhesive layer can be suppressed anddiscoloration of the touch detection electrodes TDL can be alsosuppressed, as a result, the touch detection electrodes can be madeinconspicuous.

Modification Example 1-1

Though the electric field is formed between the polarizing plate 35 andthe touch detection electrodes TDL in the above embodiment, the presentdisclosure is not limited to the above. For example, when asemiconductive layer 36 is provided between the adhesive layer 34 andthe polarizing plate 35 as a measure against ESD as shown in FIG. 14,the electric field is formed between the semiconductive layer 36 and thetouch detection electrodes TDL. The resistivity of the semiconductivelayer 36 is, for example, approximately 10⁸ [Ω·m]. Even in this case,movement of ions due to the electric field can be suppressed and thetouch detection electrodes TDL can be made inconspicuous by setting thepotential difference between the voltage Vsh of the shield electrode SHand the average voltage Vave of the touch detection signal Vdet to beequal to or less than 0.5V.

Modification Example 1-2

Though the DC current Vsens is applied to the touch detection electrodesTDL through high resistance in the above embodiment, the presentdisclosure is not limited to the above. For example, a rectangularwaveform which makes transition between the voltages VH and VL may beapplied by a given number of display frame periods instead of the above.In this case, the average voltage Vave of the touch detection electrodesTDL will be approximately an intermediate voltage between the voltage VHand the voltage VL. Also in this case, movement of ions due to theelectric field can be suppressed and the touch detection electrodes TDLcan be made inconspicuous by setting the potential difference betweenthe voltage Vsh of the shield electrode SH and the average voltage Vaveto be equal to or less than 0.5V.

3. Second Embodiment

Next, a display panel 5 according to a second embodiment will beexplained. The display panel 5 is a so-called on-cell type display panelin which the capacitance-type touch panel is formed on a display surfaceof the liquid crystal display panel. The same numerals and charactersare given to components which are substantially the same as the displaypanel 1 according to the first embodiment and the explanation isappropriately omitted.

The display panel 5 includes a display device with a touch detectionfunction 50 as shown in FIG. 4.

FIG. 15 shows an example of a cross-sectional structure of a relevantpart of the display device with the touch detection function 50. Thedisplay device with the touch detection function 50 includes a countersubstrate 51. The counter substrate 51 includes a drive electrode 52 andan insulating layer 53. The drive electrode 52 and the insulating layer53 are formed between the transparent substrate 31 and the touchdetection electrodes TDL as well as the adhesive layer 34. The driveelectrode 52 is made of, for example, ITO, having a strip-shapedelectrode pattern extending in a direction (the right and left directionof FIG. 8) orthogonal to the extending direction of the electrodepattern of the touch detection electrodes TDL (the up and down directionof FIG. 8) in the same manner as the drive electrodes COML shown in FIG.8. A touch detection drive signal Vcomt having the waveform shown inFIG. 9A is applied to the drive electrodes 52. The touch detection drivesignal Vcomt is transmitted to the touch detection electrodes TDLthrough the insulating layer 53 and the touch detection signal Vdet isoutputted from the touch detection electrodes TDL.

Also in this case, movement of ions due to the electric field betweenthe polarizing plate 35 and the touch detection electrodes TDL can besuppressed and the touch detection electrodes TDL are can be madeinconspicuous by setting the potential difference between the voltageVsh of the shield electrode SH and the average voltage Vave of the touchdetection signal Vdet to be equal to or less than 0.5V.

As the drive electrodes 52 are arranged at a position farther from thepolarizing plate 35 than a position of the touch detection electrodesTDL, the movement of ions due to the electric field between thepolarizing plate 35 and the drive electrodes 52 can be suppressed andthe drive electrodes 52 can be made inconspicuous also in this case bysetting the potential difference between the voltage Vsh of the shieldelectrode SH and the average voltage Vave of the touch detection drivesignal Vcomt to be equal to or less than 0.5V.

As described above, as the potential difference between the voltage ofthe shield electrode and the average voltage of the touch detectiondrive signal is set to be equal to or less than 0.5V in the presentembodiment, the discoloration of the drive electrodes 52 can be madeinconspicuous. Other effects are the same as the case of the firstembodiment.

Modification Example 2-1

Though the drive electrodes 52 and the touch detection electrodes TDLhave the strip-shaped electrode pattern in the above embodiments, thepresent disclosure is not limited to the above. An example will beexplained in detail below.

FIG. 16 shows an example of a structure of an upper surface of a touchdetection device in a display device with a touch detection function 50Baccording to the present modification example. FIG. 17 shows across-sectional structure of a relevant part of the touch detectiondevice shown in FIG. 16 seen from a direction of arrows XVII-XVII. Thetouch detection device includes drive electrodes 52B and touch detectionelectrodes TDLB.

The touch detection electrodes TDLB are provided in a manner whereplural partial electrodes having a square shape in this example arearranged on straight lines so that one of diagonal lines is laid out inthe up and down direction in FIG. 16 as well as corners of adjacentpartial electrodes are connected to one another. The drive electrodes52B are formed in the same layer as the touch detection electrodes TDLB,in which plural partial electrodes having a square shape in this exampleare arranged on straight lined so that one of diagonal lines is laid outin the right and left direction in FIG. 16 as well as corners ofadjacent partial electrodes are connected to one another. In this case,connection portions between partial electrodes relating to the driveelectrodes 52B bridge connection portions between partial electrodesrelating to the touch detection electrodes TDLB as shown in FIG. 17.

The shield electrode SH is formed around the touch detection electrodesTDLB and the drive electrode 52B so as to surround these electrodes asshown in FIG. 16. In the example, the shield electrode SH is formed soas to surround these electrodes from two directions other thandirections of an edge where the connection pads 39 of the touchdetection electrodes TDLB are formed and an edge where connection pads59 of the drive electrodes 52B are formed.

In the present modification example, the drive electrode 52B and thetouch detection electrodes TDLB are formed in the same layer. Therefore,the discoloration of the touch detection electrodes TDLB are suppressedand the touch detection electrodes TDLB can be made inconspicuous bysetting the potential difference between the voltage Vsh of the shieldelectrode SH and the average voltage Vave of the touch detection signalVdet to equal to or less than 0.5V as well as the discoloration of thedrive electrodes 52B can be suppressed and the drive electrodes 52B canbe inconspicuous by setting the potential difference between the voltageof the shield electrode SH and the average voltage of the touchdetection drive signal Vcomt to be equal to or less than 0.5V.

Modification Example 2-2

Though the touch detection electrodes TDL are arranged closer to thepolarizing plate 35 than the drive electrodes 52 as shown in FIG. 15 inthe above embodiment, the present disclosure is not limited to theabove, and for example, the drive electrodes 52 may be arranged closerto the polarizing plate 35 instead of the above.

Modification Example 2-3

Though the display panel 2 is the so-called on-cell type display panelin which the touch panel is integrally formed on the surface of theliquid crystal display device 20 in the above embodiment, the presentdisclosure is not limited to the above, and for example, it is possibleto form the touch panel separately from the liquid crystal displaydevice 20 and externally attached to the liquid crystal display device20 instead of the above. Also in this case, the discoloration of thetouch detection electrodes TDL can be suppressed and the touch detectionelectrodes TDL can be made inconspicuous by, for example, setting thepotential difference between the voltage Vsh of the shield electrode andthe average voltage Vave of the touch detection signal Vdet to be equalto or less than 0.5V in the single touch panel.

4. Application Examples

Next, application examples of the display panel explained in the aboveembodiments and the modification examples will be explained.

FIG. 18 shows an appearance of a television apparatus to which thedisplay panel according to the above embodiments and the like isapplied. The television apparatus has, for example, a video displayscreen unit 510 including a front panel 511 and a filter glass 512, inwhich the video display screen unit 510 is configured by using thedisplay panel according to the above embodiments and so on.

The display panel according to the above embodiments and so on can beapplied to electronic apparatuses in various fields, which are, forexample, a digital camera, a notebook personal computer, portableterminal devices such as a cellular phone, portable game machines, avideo camera and so on, in addition to the television apparatus. Inother words, the display panel according to the above embodiments and soon can be applied to electronic apparatuses in various fields whichdisplay video.

The technology according to the present disclosure has been explained asthe above by citing some embodiments, modification examples andapplication examples to the electronic apparatus, and the presentdisclosure is not limited to the above embodiments and so on and variousmodifications can be made.

For example, the shield electrode SH is formed so as to surround thetouch detection electrodes TDL from three directions in the aboverespective embodiments and so on as shown, for example, in FIG. 7 andFIG. 8, however, the present disclosure is not limited to the example.For example, when respective connection pads 39 are formed in twoopposite edges as shown in FIG. 19, it is possible to form the shieldelectrode SH so as to sandwich the touch detection electrodes TDL fromtwo directions other than the above two edges.

Additionally, for example, in the above respective embodiments and soon, the drive electrodes COML are formed on the transparent substrate 21and the pixel electrodes 23 are formed thereon through the insulatinglayer 22 as shown in FIG. 5, however, the present disclosure is notlimited to this and it is possible that, for example, the pixelelectrodes 23 are formed on the transparent substrate 21 and the driveelectrodes COML are formed thereon through the insulating film 22instead of the above.

Furthermore, for example, in the above embodiments and so on, the liquidcrystal display device using lateral-electric field mode liquid crystalsuch as FFS or IPS is integrally formed with the touch detection device,however, liquid crystal display devices using various modes of liquidcrystal such as TN (Twisted Nematic), VA (Vertical Alignment) and ECB(Electrically Controlled Birefringence) modes can be integrally formedwith the touch detection device. When such liquid crystal is used, thedisplay device with the touch detection function can be configured asshown in FIG. 20. FIG. 20 shows an example of a cross-sectionalstructure of a relevant part of a display device with a touch detectionfunction 10C according to the present modification example, showing astate in which a liquid crystal layer 6C is sandwiched between a pixelsubstrate 2C and a counter substrate 3C. As names and functions of otherportions are the same as the case of FIG. 5, the explanation thereof isomitted. The example differs from the case of FIG. 5 in a point that thedrive electrodes COML used both for the display and the touch detectionare formed in the counter substrate 3C.

Additionally, for example, the display panel 1 and the like areconfigured by using the liquid crystal display device 20 in the aboverespective embodiments and so on, however, the present disclosure is notlimited to the above, and display devices such as an EL (ElectroLuminescence) display device can be used instead of the above. Thoughthe polarizing plate is not necessary in this case, the presentdisclosure can be applied when the semiconductive layer is provided onthe display surface of the display panel as a measure against ESD in thesame manner as the modification example 1-1, as the electric field isgenerated between the semiconductive layer and the touch detectionelectrodes TDL.

The technology according to the present disclosure may be implemented asthe following configurations.

(1) A display device including

a display layer,

plural first electrodes formed to be arranged above the display layer,

a shield electrode formed apart from the plural first electrodes so asto surround the whole plural first electrodes along an arrangementsurface,

an insulating layer, and

a semiconductive layer formed opposite to the first electrodes and theshield electrode so as to sandwich the insulating layer,

in which the difference between an average potential of the firstelectrodes and an average potential of the shield electrode is equal toor less than 0.5V.

(2) The display device described in the above (1),

in which the average potential of the shield electrode is equal to orhigher than the average potential of the first electrodes.

(3) The display device described in the above (2),

in which the average potential of the shield electrode is approximatelythe same as the average potential of the first electrodes.

(4) The display device described in the above (2) or (3),

in which an arrangement area of the shield electrode is smaller than anarrangement area of the first electrodes.

(5) The display device described in any one of the above (1) to (4),

in which the semiconductive layer is an electrostatic prevention layer.

(6) The display device described in any one of the above (1) to (4),

in which the semiconductive layer is a polarizing plate.

(7) The display device described in any one of the above (1) to (6),further including second electrodes formed at the same position as thefirst electrode or a position farther from the semiconductive layer soas to sandwich the insulating layer.

(8) The display device described in any one of the above (7),

in which the first electrodes are touch detection electrodestransmitting signals corresponding to contact/non-contact and the secondelectrodes are drive electrodes forming capacitance between the secondelectrodes and the touch detection electrodes.

(9) The display device described in the above (7),

in which the second electrodes are touch detection electrodestransmitting signals corresponding to contact/non-contact and the firstelectrodes are drive electrodes forming capacitance between the firstelectrodes and the touch detection electrodes.

(10) The display device described in any one of the above (7) to (9),

in which the difference between an average potential of the secondelectrodes and an average potential of the shield electrode is equal toor less than 0.5V.

(11) The display device described in any one of the above (8) to (10),

in which the display section has

a liquid crystal layer,

pixel electrodes formed between the liquid crystal layer and the driveelectrodes, or arranged opposite to the liquid crystal layer so as tosandwich the drive electrodes.

(12) The display device described in any one of the above (8) to (10),

in which the display section has

a liquid crystal layer and

pixel electrodes arranged opposite to the drive electrode so as tosandwich the liquid crystal layer.

(13) The display device described in any one of the above (1) to (6),

in which the first electrodes are touch detection electrodestransmitting signals corresponding to contact/non-contact.

(14) A display device including

a display layer,

plural first electrodes formed to be arranged above the display layer,

a shield electrode formed apart from the plural first electrodes so asto surround the whole plural first electrodes along an arrangementsurface,

an insulating layer, and

a semiconductive layer formed opposite to the first electrodes and theshield electrode so as to sandwich the insulating layer,

in which an average potential of the shield electrode is equal to orhigher than an average potential of the first electrodes.

(15) A touch detection device including

plural first electrodes,

a shield electrode formed apart from the plural first electrodes so asto surround the whole plural first electrodes along an arrangementsurface,

an insulating layer, and

a semiconductive layer formed opposite to the first electrodes and theshield electrode so as to sandwich the insulating layer,

in which the difference between an average potential of the firstelectrodes and an average potential of the shield electrode is equal toor lower than 0.5V.

(16) An electronic apparatus including

a display device, and

a control unit performing operation control using the display device,

in which the display device includes

a display layer,

plural first electrodes formed to be arranged above the display layer,

a shield electrode formed apart from the plural first electrodes so asto surround the whole plural first electrodes along an arrangementsurface,

an insulating layer, and

a semiconductive layer formed opposite to the first electrodes and theshield electrode so as to sandwich the insulating layer, and

the difference between an average potential of the first electrodes andan average potential of the shield electrode is equal to or less than0.5V.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention is claimed as follows:
 1. A display device comprising: afirst substrate; a second substrate opposed to the first substrate; apolarizing plate arranged on the second substrate; a resistive layerarranged between the second substrate and a polarizing plate, theresistivity of which is in a range of 10 [Ω·m] to 10¹³ [Ω·m]; a liquidcrystal layer arranged between the first substrate and the secondsubstrate; a plurality of detection electrodes arranged between thefirst substrate and the resistive layer; a shield electrode arrangedbetween the first substrate and the resistive layer, and the shieldelectrode being apart from the detection electrodes in a plane view; andan insulating layer arranged on the detection electrodes and the shieldelectrode, and wherein the detection electrodes and the shield electrodeare overlapped by the resistive layer in a plane view.
 2. The displaydevice according to claim 1, wherein the detection electrodes arearranged in a detection area, a shape of the detection area beingquadrangle, and wherein the shield electrode is arranged along at leasttwo side of the detection area.
 3. The display device according to claim1, further comprising a pixel electrode arranged on the first substrate,wherein the detection electrodes include a drive electrode supplied witha drive signal and a touch detection electrode to output a detectionsignal based on the drive signal, and wherein the liquid crystal issupplied with a voltage between the pixel electrode and the driveelectrode.
 4. The display device according to claim 1, wherein thedetection electrodes include a drive electrode supplied with a drivesignal, the drive electrode coupled to a terminal via a wire, andwherein the shield electrode extends across the wire in a plane view. 5.The display device according to claim 1, wherein the shield electrode isconfigured to be supplied with a DC voltage.
 6. The display deviceaccording to claim 1, wherein the shield electrode is configured to beconstantly supplied with a DC voltage.
 7. The display device accordingto claim 1, wherein the shield electrode is configured to be suppliedwith a DC voltage for a predetermined period before or after a touchdetection signal being output from the plural touch detection electrodesmakes transition.
 8. The display device according to claim 1, whereinthe difference between an average potential of the plural touchdetection electrodes and an average potential of the shield electrode ismore than 0.0V and less than 0.5V.
 9. The display device according toclaim 1, wherein an average potential of the shield electrode is equalto or higher than an average potential of the touch detectionelectrodes.
 10. A display device comprising: a first substrate; a secondsubstrate opposed to the first substrate; a polarizing plate arranged onthe second substrate; an electrostatic prevention layer arranged betweenthe second substrate and a polarizing plate; a liquid crystal layerarranged between the first substrate and the second substrate; aplurality of detection electrodes arranged between the first substrateand the electrostatic prevention layer; a shield electrode arrangedbetween the first substrate and the electrostatic prevention layer, andthe shield electrode being apart from the detection electrodes in aplane view; and an insulating layer arranged on the detection electrodesand the shield electrode, and wherein the detection electrodes and theshield electrode are overlapped by the electrostatic prevention layer ina plane view.
 11. The display device according to claim 10, wherein thedetection electrodes are arranged in a detection area, a shape of thedetection area being quadrangle, and wherein the shield electrode isarranged along at least two side of the detection area.
 12. The displaydevice according to claim 10, further comprising a pixel electrodearranged on the first substrate, wherein the detection electrodesinclude a drive electrode supplied with a drive signal and a touchdetection electrode to output a detection signal based on the drivesignal, and wherein the liquid crystal is supplied with a voltagebetween the pixel electrode and the drive electrode.
 13. The displaydevice according to claim 10, wherein the detection electrodes include adrive electrode supplied with a drive signal, the drive electrodecoupled to a terminal via a wire, and wherein the shield electrodeextends across the wire in a plane view.
 14. The display deviceaccording to claim 10, wherein the shield electrode is configured to besupplied with a DC voltage.
 15. The display device according to claim10, wherein the shield electrode is configured to be constantly suppliedwith a DC voltage.
 16. The display device according to claim 10, whereinthe shield electrode is configured to be supplied with a DC voltage fora predetermined period before or after a touch detection signal beingoutput from the plural touch detection electrodes makes transition. 17.The display device according to claim 10, wherein the difference betweenan average potential of the plural touch detection electrodes and anaverage potential of the shield electrode is more than 0.0V and lessthan 0.5V.
 18. The display device according to claim 10, wherein anaverage potential of the shield electrode is equal to or higher than anaverage potential of the touch detection electrodes.
 19. A displaydevice comprising: a first substrate; a second substrate opposed to thefirst substrate; a polarizing plate arranged on the second substrate; aresistive layer arranged between the second substrate and a polarizingplate, the resistivity of which is in a range of 10 [Ω·m] to 10¹³ [Ω·m];a liquid crystal layer arranged between the first substrate and thesecond substrate; a plurality of detection electrodes arranged betweenthe first substrate and the resistive layer; and a shield electrodearranged between the first substrate and the resistive layer, and theshield electrode being apart from the detection electrodes in a planeview, and wherein the detection electrodes and the shield electrode areoverlapped by the resistive layer in a plane view.